?? PostgreSQL ??? ??? JSON ?? ??
? ?????? PostgreSQL ????? ???? ?? ??? ????? JSON ?? ??? ???? ??? ?????. ????? MyTable ???? ??? ?????.
| id | value_two | value_three | value_four |
|---|---|---|---|
| 1 | a | A | AA |
| 2 | a | A2 | AA2 |
| 3 | b | A3 | AA3 |
| 4 | a | A4 | AA4 |
| 5 | b | A5 | AA5 |
??? value_three?? ???? value_four ? value_two? ???? ? ??? ??? JSON ??? ??? ????. ??? ?? ??? ??? ????.
| value_two | value_four |
|---|---|
| a | [{"value_three":"A","value_four":"AA"}, {"value_three":"A2","value_four":"AA2"}, {"value_three":"A4","value_four":"AA4"}] |
| b | [{"value_three":"A3","value_four":"AA3"}, {"value_three":"A5","value_four":"AA5"}] |
PostgreSQL ???(???)
??? ???? PostgreSQL ??? ?? ????.
PostgreSQL 10 ??:
? ??? ?? - ???? ???? ??? ??????.
SELECT val2, jsonb_agg(to_jsonb(t.*) - '{id, val2}'::text[]) AS js_34
FROM tbl t
GROUP BY val2;
??? ?? ?? ?? ???? ?(id ? val2)? ????? ?????.
PostgreSQL 9.4 ??:
jsonb_build_object() ? ??? ?? ??? ?????.
SELECT val2, jsonb_agg(jsonb_build_object('val3', val3, 'val4', val4)) AS js_34
FROM tbl
GROUP BY val2;
?? ? JSON ??? ?? ?-? ?? ????? ?????.
PostgreSQL 9.3 ??:
?? ?? ??? ??? ?? ???? ????.
-
to_jsonb((val3, val4)): ?? JSON?? ? ??? ?????. -
??? ???? ???.(val3, val4)::foo: ??? ?? ? ??(foo)?? ???? ? ??? ?????.CREATE TYPE foo AS (val3 text, val4 text);??? -
?? ?? ?? ??: ?? ??? ???? ?? ??? ????? ?? ???? ????.
SELECT val2, jsonb_agg(to_jsonb((val3, val4))) AS js_34 -- Loses column names FROM tbl GROUP BY val2; -- Requires: CREATE TYPE foo AS (val3 text, val4 text); SELECT val2, jsonb_agg((val3, val4)::foo) AS js_34 -- Preserves column names FROM tbl GROUP BY val2; SELECT val2, jsonb_agg(to_jsonb((SELECT t FROM (SELECT val3, val4) t))) AS js_34 -- Subquery approach FROM tbl GROUP BY val2;
PostgreSQL ??? ??? ??? ??? ?? ??? ??? ?????. ?? 10 ??? ?? - ???? ?? ???? ???? ???? ?????.
? ??? PostgreSQL?? ?? ?? JSON ?? ??? ???? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!
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